Cyclocondensation of coumarin-3-thioformates with 3-hydroxyoxindoles and 3-aminooxindoles for the synthesis of spiro-fused pentaheterocyclic compounds

Abstract

A range of spiro-fused pentaheterocyclic compounds including spiro-butyrolactoneoxindole[3,4-<italic>c</italic>]coumarins and spiro-butyrolactamoxindole[3,4-<italic>c</italic>]coumarins were smoothly obtained <italic>via</italic> tandem Michael addition-lactonization/lactamization process.